[Wien] Difference between "x lapw2 -qtl" and "x qtl"
Rubel, Oleg
rubelo at mcmaster.ca
Wed Mar 15 02:58:01 CET 2023
Dear Lukasz,
sorry, I do not have a direct answer, but you might consider checking files case.normsoup and case.normsodn. They contain alpha^2 (normsoup) and beta^2 (normsodn) spinor components for each k point and each eigenvalue (check that alpha^2 + beta^2=1). I would compare alpha^2 vs beta^2 for a k point and eigenvalue of interest to see if one of them dominate. These are plane text files and easy to read. Here is the subroutine for reading used in fold2Bloch https://github.com/rubel75/fold2Bloch-Wien2k/blob/master/read_norms.F90 It is called sequentially for each k point. The number of eigenstates (NE) sometimes changes from one k point to another.
Best regards
Oleg
> -----Original Message-----
> From: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> On Behalf Of
> pluto via Wien
> Sent: Tuesday, March 14, 2023 8:32 PM
> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> Cc: pluto <pluto at physics.ucdavis.edu>
> Subject: [Wien] Difference between "x lapw2 -qtl" and "x qtl"
>
> Dear All,
>
> I am calculating one of the 1T TMDC materials. This material e.g. has a spin-
> polarized Dirac cone on the surface (see e.g. DOI
> 10.1088/2516-1075/ab09b7 for review of similar materials).
>
> I calculated 10L (15 inequivalent atoms) and 20L (30 inequivalent atoms)
> slabs. I allowed sgroup to find the space group (no. 164) in order to speed up
> the calculation. In this case it means each inequivalent atom has 2 equivalent
> positions.
>
> It is a spin polarized calculation with SOC. Band structures look good
> compared to the literature Wannier calculations.
>
> One obvious test is to check spin polarization of the Dirac cone.
>
> Band characters can be calculated either using x lapw2 -band -qtl -up/dn -so
> (default in w2web) or using x qtl -band -up/dn -so
>
> Importantly, in order to make x qtl work I need to cp case.in1 case.in1c
> although the system does have inversion (otherwise qtl gives an error and
> nothing is calculated). Is this allowed?
>
> Another problem is that for the 20L slab x spaghetti does not want to plot fat
> bands out of case.qtlup/dn produced by "x qtl". I didn't look at the
> case.qtlup/dn files in detail yet (I will, but it might take a while), but either they
> are incomplete (i.e. x qtl cannot handle a big slab), or spaghetti cannot handle
> these files beyond a certain size limit. On the other hand case.qtlup/dn
> produced by x lapw2 always work with fat bands. Of couse when using x qtl I
> limit the number of atoms in case.inq, and I typically only calculate characters
> for 2 outermost atoms (my case.inq pasted below). For 10L slab everything
> works fine.
>
> The plotted results (using w2web) for these two cases look very different. I
> tried plotting characters on couple of outermost atoms.
>
> x lapw2 does not show any spin polarization of the Dirac cone x qtl shows
> clear very high polarization of the Dirac cone
>
> This happens when I plot total character on a particular atom, is it not an
> effect related to some Y_lm character or things like that.
>
> I think in general I should split all atoms in order to get correct spin
> polarization (the so-called hidden spin polarization introduced by
> Zunger/Freeman). This is what one had to do with the 2H MoS2 calculations
> several years back. But splitting all atoms would probably make 20L slab
> calculation prohibitive on my system (I think 20L would be unrealistic).
>
> But perhaps the QTL program can somehow do the job of splitting the
> equivalent atoms even on slab with equivalent positions.
>
> I also paste below case.inso, note that the direction of spin polarization quant.
> axis is along 100, i.e. in-plane, as it should for these materials.
>
> Best,
> Lukasz
>
>
> case.inq file:
>
> -9.0 3.0 Emin Emax
> 2 number of atoms
> 1 1 0 1 iatom,qsplit,symmetrize,locrot
> 3 0 1 2 nL, l-values
> 0 0 1
> 30 1 0 1 iatom,qsplit,symmetrize,locrot
> 3 0 1 2 nL, l-values
> 0 0 1
>
> case.inso
>
> WFFIL
> 4 0 0 llmax,ipr,kpot
> -10 1.9 Emin, Emax
> 1 0 0 h,k,l (direction of magnetization)
> 30 number of atoms with RLO
> 1 -3.53 0.0001 STOP atom-number, E-param for RLO
> 2 -3.53 0.0001 STOP atom-number, E-param for RLO
> 3 -3.53 0.0001 STOP atom-number, E-param for RLO
> 4 -3.53 0.0001 STOP atom-number, E-param for RLO
> 5 -3.53 0.0001 STOP atom-number, E-param for RLO
> 6 -3.53 0.0001 STOP atom-number, E-param for RLO
> 7 -3.53 0.0001 STOP atom-number, E-param for RLO
> 8 -3.53 0.0001 STOP atom-number, E-param for RLO
> 9 -3.53 0.0001 STOP atom-number, E-param for RLO
> 10 -3.53 0.0001 STOP atom-number, E-param for RLO
> 11 0.30 0.0000 CONT atom-number, E-param for RLO
> 12 0.30 0.0000 CONT atom-number, E-param for RLO
> 13 0.30 0.0000 CONT atom-number, E-param for RLO
> 14 0.30 0.0000 CONT atom-number, E-param for RLO
> 15 0.30 0.0000 CONT atom-number, E-param for RLO
> 16 0.30 0.0000 CONT atom-number, E-param for RLO
> 17 0.30 0.0000 CONT atom-number, E-param for RLO
> 18 0.30 0.0000 CONT atom-number, E-param for RLO
> 19 0.30 0.0000 CONT atom-number, E-param for RLO
> 20 0.30 0.0000 CONT atom-number, E-param for RLO
> 21 0.30 0.0000 CONT atom-number, E-param for RLO
> 22 0.30 0.0000 CONT atom-number, E-param for RLO
> 23 0.30 0.0000 CONT atom-number, E-param for RLO
> 24 0.30 0.0000 CONT atom-number, E-param for RLO
> 25 0.30 0.0000 CONT atom-number, E-param for RLO
> 26 0.30 0.0000 CONT atom-number, E-param for RLO
> 27 0.30 0.0000 CONT atom-number, E-param for RLO
> 28 0.30 0.0000 CONT atom-number, E-param for RLO
> 29 0.30 0.0000 CONT atom-number, E-param for RLO
> 30 0.30 0.0000 CONT atom-number, E-param for RLO
> 0 0 number of atoms without SO, atomnumbers
>
>
>
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